update

README.md

@@ -9,7 +9,9 @@ AWS assume role credential wrapper.
 
 awscredswrap uses temporary credentials for the specified iam role to set a shell environment variable or execute a command.
 
-## Install
+## Use as CLI
+
+### Install
 
 - Brew
 
@@ -19,7 +21,7 @@ $ brew install youyo/tap/awscredswrap
 
 Other platforms are download from [github release page](https://github.com/youyo/awscredswrap/releases).
 
-## Usage
+### Usage
 
 ```bash
 $ awscredswrap --help
@@ -37,13 +39,13 @@ Flags:
       --version                    version for awscredswrap
 ```
 
-### As command wrapper
+#### As command wrapper
 
 ```console
 $ awscredswrap --role-arn arn:aws:iam::00000000:role/foo -- some_command [arg1 arg2...]
 ```
 
-### As env exporter
+#### As env exporter
 
 When awscredswrap is executed with no arguments, awscredswrap outputs shell script to export AWS credentials environment variables.
 
@@ -63,6 +65,57 @@ $ eval $(awscredswrap --role-arn arn:aws:iam::00000000:role/foo)
 
 Temporary credentials has expiration time (about 1 hour).
 
+---
+
+## Use as GitHub Actions
+
+### Inputs
+
+#### `role_arn`
+
+**Required** The arn of the role to assume.
+
+#### `role_session_name`
+
+An identifier for the assumed role session. (default awscredswrap@GitHubActions)
+
+#### `duration_seconds`
+
+The duration, in seconds, of the role session. (default 3600)
+
+### ENV
+
+- `AWS_ACCESS_KEY_ID` **Required**
+- `AWS_SECRET_ACCESS_KEY` **Required**
+- `AWS_DEFAULT_REGION` **Required**
+
+Recommended to get `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` from secrets.
+
+### Example usage
+
+```yaml
+on: [push]
+
+jobs:
+  assume_role:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Assume Role
+        uses: youyo/awscredswrap@master
+        with:
+          role_arn: ${{ secrets.ROLE_ARN }}
+          duration_seconds: 3600
+          role_session_name: 'awscredswrap@GitHubActions'
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          AWS_DEFAULT_REGION: 'ap-northeast-1'
+      - name: Identity Check
+        uses: actions/aws/cli@master
+        with:
+          args: sts get-caller-identity
+```
+
 ## License
 
 [MIT](LICENSE)